In order to increase the power or efficiency of internal combustion engines, use may be made of turbochargers or exhaust-gas turbochargers (EGTs). A turbocharger has a compressor for inlet air and an exhaust-gas turbine. The compressor is integrated in the air intake system of the internal combustion engine to increase the air throughput and to reduce the suction work of the pistons of the internal combustion engine. The compressor of the turbocharger is driven by the exhaust-gas turbine Specifically, a turbine wheel of the exhaust-gas turbine drives a compressor wheel of the compressor by means of a shaft which rotates with the turbine wheel. During operation, hot exhaust gases from the combustion chambers of the internal combustion engine flow through the turbine wheel of the exhaust-gas turbine and consequently drive said turbine wheel. Downstream of the turbine wheel, a diffusor is provided in the turbine housing for improving the outflow of the exhaust gas from the turbine wheel. The use of the diffusor makes it possible to improve the efficiency of the exhaust-gas turbine. The diffusor can be cast as a region of the turbine housing. This means that exhaust gas flowing through the exhaust-gas turbine requires a design of the thermally highly loaded turbine housing that is tailored to said exhaust gas.
In confined installation situations, it may be necessary to connect an exhaust-gas manifold to an outlet of the turbine of the turbocharger. The exhaust-gas manifold allows a deflection of the flow direction of the exhaust gas for channeling it into further components of the exhaust-gas system, for example modules for exhaust-gas aftertreatment.
The diffusor length is limited through its integration into the turbine housing. Moreover, a relatively long diffusor, and thus a relatively large and relatively long turbine housing, has a negative impact in terms of the installation space and the arrangement of components of the exhaust-gas train that are provided downstream. In particular, it may be necessary for an exhaust-gas manifold provided downstream to be provided with a smaller bending radius, i.e. to curve the exhaust-gas manifold more significantly. An exhaust-gas manifold having a smaller bending radius has a negative impact on the outflow from the exhaust-gas turbine and can reduce the efficiency of the exhaust-gas turbine.